Automatic drill head



June 6, 1950 P. s. CLAUS AUTOMATIC DRILLHEAD 3 Sheets-Sheet 1 Filed June 25, -1945 N am QN w. @QA ww mv mm mm NS s wm@ @n .N km ma d @W M/ AWMMAMAW/ mm.

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MW mw e ma a NL r .IC W ev. .a W M m P. s. CLAUS vAu'roMA'rIc DRILL HEAD `lune 6, 1950 3 Sheets-Sheet 2 Filed June 23, 1945 INVENToR. P//L/P CL H05 /"atentecl-l .lune 6,

Philip. S. Claus, Elymoutm Michlassienor .to William A. King, Highland Bark, Mich.;

trustee Application June es, 1945.., serlallvo. 601,146

6 claims. (o1. 7'1-3'3) 1 My inventionrelates to iniprovementsA in ,automaticv drill headand has todoimor-e partielle., ly. wthan improved automatic feeding melhaism forfeeding a rotary cutter, such as a drill Ql reamer, toward the Work.

, Oney principal object or my` invention .is to provide, in ari-automatic drill head, imoroved means for automatically reducing the ieeding pressure electiveonthe rotary drill orcuttel, .at @predetermined point in the feed thereof. l

A further object of my invention is to DlTQvide, in an automatic drill head, iifloroved means ier automatically..increasing the feeding pressure eifetive 011 the rotary ir-.ill or cutter, soon after the beginnneof the feed thereof.

Aiurtlier object of my inventionis to provide improved means vfor,automatically feeding toward the work the rotary drill or cutter of an automatic drill head, which Will have the known advantages of spherical inertia members coupled with the advantage of using thev largest inertia mass possible within the space limits of. the toll Another principal object of my inventlollis t9 provide an, automatic drill head havineimproved means of advancing or feeding automatically the rotary drill or cutter toward the Work, AOtelloh nature that the braking effort required to bring the vmotor drivenshaft and tool-carrying spindle to normal positions of rest will be reduced to minimum- A further object of my invention is to provide such automatic feeding mechanism 'so cn- `st rulcted that the mass of the rotatingparts, Whose momentum must be` absorbed by the braking elort at the conclusion of vthe feed, is greatly reduced.

A further object of my invention is to provide an automatic feeding mechanism kfor automatic drill heads, in .which it is not necessary to overL come the momentum of the inertia mass used to develop feeding pressure, to bring the driving motor, and the shafts and tool-carrying' spindle driven thereby, to rest.

A'further object of my invention is to provide, in an automatic drill head, an improved mechanism for automatically feeding the rotary drill or cutter toward the Work so constructed as tospee'd up the operating cycle by reducing the time required'to restore the 'parts to normal at the end`-of the feed.

Further objects, and objects relating to details and economies of construction and operation, Will definitely appear from the detailed'description to follow. In one instance, lI have accomplished the objects of my invention by the devices and means disclosed inthe follwingespecflcation. My invention is distinctly pointed out in the appended claims. A structure, constituting a preferred embodiment of my invent-ionfi's shownin the accompanying drawingsftorrning a partof this speciilcation;ina/vluchtY Y Y Fig. y,l is la longitudinal,y sectional viewthrough an automatic drill head rerr-ilootdying my inl/iene tion.

Fig. '2 is an enlarged, sectional View, correspondingto a part of Fig. .1., showing the cage, sockets` and balls .with the frustoeconical pusher mernlrerV in advanced position, this member being shown in normalposition by. dottedllines. Y

Fig. Sis adetail, sectional view, taken on the line 313 of -FigZ Fg'wisa detail, .sectional view, taken on the line 4?--4 of.Fig-.2.

vInthe drawings, the sametreference vr'iumerals referto the samelparts .throughout the several views, andthe sectional .views are taken looking in the directionof thearrovvs at they ends ofv thesec: tionlines. This inventionis an improvementon the vini/'fmtion disclosed in the :impending ,appli-`v cation of Bhilios. .Claus and 4Eber J. Readman, Serial No. 582,646 now U. S; Patent No. 2,421,5fll, issued` June 3, 1947. Onefeature of mypresent invention consists ira-.the Luse of inertia masses; for developing feeding pressure to advance the rotary tool toward the Work, which comprise a pluraltyof holders, mounted in a revolulole re.M tainer driven by the driving shaitl and movable outwardly thereof; :and a plurality of ine ia members carried by these holders and mollibl outwardly therein. The inertia members engage a. truste-conical pusher member, Whichis connected to thedriven4 shaft or, spindle .so that the pressure exerted on ithe pusher member by the in: erti'a members and holders, upon rotation oi the retainer, `is transmitted to .the driven Shaft 159 move 4it axially.V y'f1/he retainer may take. i?, Dllll of a cageandlthelholders; may besooketsslidably mounted inthelcage and receivingballs that con-l stitute the inertia-members. The holders or sock-- ets, and the inertia members Whiehlorei'ereloly rolling members .s1-.lolitas loalis; maybe ,so/guided as to move radiallyfofthe driving lflazft- Mall they. be providedv ,if or limiting the outwardmovement of the holders in theretainer so that-When ,the h l e ers reach theirlonter limit otenet/ement, the ertia members may move out of thrust relationship'therewith,l thusv redllellg the inertia mass effective to vdevelop needing pressure.

Another feature .ofzmy present invention. con,- sists in providing; a one-way driving conne@tieni` or overrunning clutch' connection, between the driving .shaft .andfy'the retainer .or cage il r thev ir- 1f ertia members .or .balise lsfo ,when the motor drives theshafn-.theretainer vwill henri-ven there.- loy., but, Wl'nanztliemotorv ceases kStoldrive vthe shaftl the connection .yvilf be ineffective andthe reta and inertia mass, rotatngdue to kjnuimei; in, will not drive thefshaft. This -leature .perm-itso speeding up the .operating vcycle since less :timeie required to restoretthelparts to normalat the end oflthe feed,- .andfit Willilake'lessnbraking eortto bringthey motor, shattsand spindleto rest:

Referring to the numbered parts of the drawings, an improved automatic drill head embodying this invention is provided with a casing which includes a rear member 5 for mounting the motor, having a forwardly-extending cylindrical part 6, provided with a radial flange 1. The main portion of the casing consists of cylindrical member I0, which has a rear portion of greater diameter than its forward portion, and which seats against the bearing support 8 and is secured thereto and to the flange 1, by screws lI and I2. The forward portion 0f the casing is formed by a cylinder i3, which fits within the forward portion of cylinder I0 and is secured thereto by screws I4. The cylinder i3 is provided with an internal annular flange l5. A rotatable adjusting member I6 has an annular shoulder I1, and an annular flange i8, and the adjustable member Iii fits within the forward end of cylinder I3 with the shoulder I1 adapted to engage the inner face of ange I5, and the flange I8 engaging the front face of said flange i5. A ball bearing 28 is seated in the forward portion of the adjusting member I6, in a seat I3, and the spindle 40 is journaled in said ball bearing. A retaining member 2l ts within the forward end of adjusting member I6 and is secured thereto by screws 22, and this retaining member engages the ball bearing 2l) and holds it in its seat I9. A ring 23 is mounted within the casing member I3 and engages the forward face of iiange I8 on the adjusting member I5. A ring 24 is seated within the forward end of the casing member i3 and held in position by a split ring 28, seated in a groove 2l in the casing member. The ring 24 has a plurality of symmetrically arranged sockets 25, in each of which a spring 26 and ball 26a are seated, said balls engaging the forward face of ring 23 and pushing it toward the flange I8.

An electric motor 3U is mounted in the casing member 5, and the armature shaft 3l of the motor is connected through a coupling 32 to the driving shaft by the transverse taper pin 34. The shaft 33 is journaled in the bearing support 8, a little in front of the point at which it enters the hub of the coupling member 32, by the ball bearing 35, mounted in said bearing support 8. The sleeve 36 is mounted on shaft 33 and a stud 31, carried by said sleeve, engages in a longitudinal groove 38 in the shaft. The forward end of sleeve 36 is connected by the transverse taper pin 39 to the rear end of the spindle 40, which eX- tends within the sleeve. Thus, the driven shaft or spindle 45 is coaxial with the driving shaft 33 and rotatable with said shaft, but movable longitudinally thereof. The front end of the spindle 45 is provided with a socket 4I, adapted to receive the shank of a rotary cutter.

To automatically advance the spindle 48 as the shaft 33 rotates, together with said spindle, a feed sleeve 42 is provided, coaxial with shaft 33 and mounted upon the outside of sleeve 36. A stud 43, carried by the feed sleeve 42, engages in a longitudinal groove 44 formed in sleeve 36, so that the sleeve rotates with the driving shaft 33 but is movable longitudinally with respect thereto. A ring 45, secured to the rear end of sleeve 42, has secured thereto a frusto-conical pusher member, including the forward portion 46, the intermediate portions 41 and 41a, the intermediate portion 41 being of greater slope than the forward portion 46, and the intermediate portion 41a of the same slope as the forward portion 46, and the rear cylindrical portion 48. The retainer or cage 43 is revolubly mounted on the shaft 33 and its forward face engages shoulder 49a. on said shaft. Also mounted on the shaft 33 is an overrunning clutch or one-way driving connection consisting of an outer member 5U, an inner drive member 5|, and interposed rollers 52, which are adapted to be engaged by the cam surfaces 53 of the drive member, and said rollers upon rotation of the drive member become wedged between the inner and outer members of the clutch. The rollers are permitted slight radial movement in the neutral position, when each lies adjacent a stop 54 at the base of cam surface 53. A key 55, carried by the drive member 5I, engages in a longitudinal groove 56 formed in the shaft 33, so that said drive member is keyed to the shaft. The outer member 58 of the clutch has an inwardly-extending flange 9 at its rear end, which prevents rearward movement of rollers 52. Cage 49 has a rearwardly-extending cylindrical flange 28, coaxial with shaft 33, within which the overrunning clutch is housed. A key 63 carried by flange 23 lits in keyway 9D in the outer portion of outer member 58, to nx the latter in said annular flange.

The cage 43 is provided with a plurality of radial bores 51, symmetrically arranged about the axis of shaft 33. The bores 51, have mounted therein sockets 58, which substantially fill said bores and are provided on their rear faces with longitudinal grooves 53, which receive stop screws 68 carried by cage 43 and limiting the outward movements of the sockets with respect to the cage. Notches 9i are provided in the -exterior of flange 23 to provide access to the heads of stop screws 68 for insertion or removal thereof. The sockets 58 are provided with recesses 6I in their outer ends, which receive the centrifugal balls 62. The cage 49, sockets 58 and balls 62 are housed within the frusto-conical pusher member and, when the shaft 33 is at rest, the balls engage the steeper portion 4l of said pusher member.

When shaft 33 starts rotation, balls 62 engage the steeper portion 41 of the pusher member and consequently a larger proportion of the centrifugal :force exerted by the balls 62 is effective to move the pusher member and feed sleeve 42 axially, to start the tool feed. At the start of the feed, however, friction between sockets 58 and the walls of bores 51 may hold back the sockets momentarily so that the balls move outwardly in recesses 8l and only the mass of balls 62 is eiective to develop centrifugal force transmitted to the pusher member. Centrifugal force acting on the sockets 58 soon overcomes any frictional resistance, and said sockets move outwardly into thrust relationship with balls 62, so that the mass of both sockets and balls is effective to develop centrifugal force exerted on the pusher member. Early in the feed of t'he tool the balls 62 pass from engagement with the steeper portion 41 to engagement with the less steep portion 41a of the pusher member, whereby the proportion of the centrifugal force, effective to move the pusher member axially, is reduced. At a predetermined point in the feed of the pusher member, feed sleeve and tool, preferably near the end of the feed, stop pins 68 engage the inner ends of grooves 59, so that further outward movement of the sockets is prevented and, thereafter, the only centrifugal force effective to feed the tool is that due to balls 62, alone. Thus, the lpressure developed by centrifugal force and exerted on the.

andere pusher member to' feed) the' tool is reducedV at' a predetermined point in the feed.

The inner race of a ball bearing 63 is mounted the sleeve 42, in front of thel ring 45, and a spring seat 64 is mounted on the outer race of the ball bearing'. A coiled compression spring 65 is v-iizdzerposed between the spring seat `ISII and the rearfend of the cylindrical casing member I3. This spring yieldingly opposes the advance of the feed sleeve 42 as the shaft` rotates and, when the shaft is brought to rest, this `rspring returns the feed sleeve 42 and pusher member tothe normal position, shown in Fig. 1.

viA-fspherical -portion 66 is formed on the spindle 40,- a't the rear end thereof, and a transverse pin 61 extends through the spindle, a short distance in 'the' 'rear' of this ball portion. Al collet sleeve 68 is mountedf on the spindle, surrounding it, with the interior of the 'forward portion of the sleeve "engagement with the yball portion 66 of thespin'dle and with the endsof lthe transverse pin 61 projecting into inclined slots 10 vin .the collet sleeve 68,diarnet'rically oppositefeach other. n the frear portion of the collet sleeve 68, there isformed an external frusto-conical shoulder A68. A transverse socket 1I is formed i-n-the spindle, in the rear of the pin 61, and this `socket houses a plunger 12, which engages the inside of the rearp'ortion -of the colletsleeve and :is pressed upwardly against vthe vsleeve Aby the spring '1.3 housed in the socket. 'This spring-pressed plu-nger' l12 norm-ally 'rocks the 'collet about its pivotal mounting on the spindle, so that theiaxis vof the collet sleeve 68 extends at an angleto l"the .axis of the shaft 33 and spindle 40, and, under A'such conditions, the rea-r -end of thecolle'tsleeve projectsfinto the path of the feed sleeve 42, so that, as the feed sleeve isfautomatically.advanced upon rotation 4'of the shaft, -th'e cock-'edcollet sleeve transmits this `feeding motion 'to the spindle y40. When the collet sleeve `is rocked, vso fas to bring its axis into alignment with the ax-is of shaft 33=andvspindle 48, the collet sleeve..68 :and spindle -40 will be retracted, to withdraw thetool from tllework,the 'collet passing within the forward/end ofthe Yfeed sleeve 42. vThis is brought about Aby the -coiled lcompression spring '14, interposed between `the forwardend of the collet sleeve-68 and the inner race of the ball bearing 28, whichspring yieldingly opposes the advance of the Vspindle and pulls '-it away Ifrom the -work assoon as "the collet sleeve 68 is tilted ifrom the cocked position into i concentricity Awith-'the feed sleeve 42. The -inclinationof thes'lots `1l] is such thatfthe rocking yof -thecollet sleevev 68, from `its cocked 'te its concentric positionfcauses :a-'slight relative movement of thes-pindle 48 land the co1-v let sleeve 68 to retract 'the spindle-slightly vat the instant of discontinuance of #the spindle feed. Thereater, Y`'the spindle -is 'completely retracted by the pressure offspring 1=4.

Abra-ke sleeve -1-5-is mounted within the cylindrical casing member I3 and held against rotation with respect thereto, while "permitting 1ongitudinal movement, by ,means cf a key 16..-.carried by casing member I3 and aerrgagi-ngin Ythe longitudinal groove `11 formed inthe outer surface of the brake sleeve. The rfor-ward end of said brake sleeve has an inwardly extending anriular flange `18, which is vinternally "threaded and engages the 'externally threaded portion 19 'of the rotatable adjusting umember vI6. Upon 'ro'- tatingithe ladjusting member Ii6, the brakesl'eeve T vwill `be'fheld against'rotation with respect to the casing, and will therefore be adjusted longitudinally Vof the. casing t3. Therear' portion-ofthebrake sleeve 15 carries a. brake ring 82 xed thereto by pins 81. This brake ring 82 has an outwardly extending annular flange .83, adapted to be engaged by a brake flange 84xed to the feed sleeve 42.

The outer race85 of a ball bearing is mounted within the brake sleeve 15, in .engagement with the front `face of the brake ring 82. Balls 86 of the bearing are interposed between the outer race v85 and the inner racev 81, which surrounds the spindle 40 and is coaxial with shaft 33 and spindle 40. A coiled compression spring 88 is interposed between the outer race 85 of this ball bearing and the rear face of the flange 18, and yieldingly holdsy the lbearing race 85 against the front face of brake ring 82. Thus, by rotating the adjusting member I6, the brake sleeve 15 will be adjusted longitudinally of the casing member I3 and the inner race 85 of the ball bearing and the brake ring 82 will be vpositioned accurately, to cause the spindle feed to be discontinued alt a predetermined point. As the spindle 40 is advanced, the forward end of the collet 88 will enter the annular race 81 and, when the frustoconical portion 69 of the collet engages the an nular race 81, the collet 68 will be rocked into concentric relation with the axis of shaft 33 and spindle 48 to discontinue the spindle feed.

Fig. l illustrates the positions occupied by the parts of this mechanism, when the power is cut off from the motor 30 and. the driving shaft 33 is at rest. The collet 68 is cocked, so as to project a portion of the rear end thereof in the path of advance of the feed sleeve 42. When the switch is closed, to supply current to the motor 38, shaft 33 is driven, thus causing the drive member 5I fixed to shaft 33 to be rotated and the rollers 52 to become wedged between the cam surfaces 53 of drive member 5I and the outer member 56 of the overrunning clutch mechanism, and causing the revoluble cage 49 to rotate. As the shaft 33 rotates, the balls 52 and sockets 58 exert centrifugal force on the pusher member to advance the feed sleevev 42. Thus, the feed sleeve 42 is advanced automatically, as the shaft rotates, against the yielding pressure of spring 65. The advance of the feed sleeve 42, through collet 68, causes the spindle to advance. When the spindle 48 is advanced to the predetermined position, the frusto-conical portion 69 of the collet 68 engages the inner race 81 fof the ball bearing to rock the collet 68 on its pivotal mounting on the spindle 48, to bring it into concentric relation with the axis of shaft 33. As soon as the collet becomes concentric with the axis of shaft 33, compressed spring 14 becomes effective to withdraw the spindle and move the collet 68 rearwardly into the forward end of the feed sleeve 42. The advance of the feed sleeve 42 will have brought the brake flange 84 into engagement with the brake ring 82, which tends to bring the shaft 33 andthe parts driven thereby to rest. When the circuit to the motor is automatically opened at this point, the stopping of the motor drive will result in the rollers A52 :becoming :disengaged from the outer member 58 of thef-overrunning lclutch so that lthe drive of the revoluble ca'ge is disconnected. The braking effort of brake flange 84 against brake ring 82, thereforadoes not'have to overcome the momentum of cage-49, sockets 58 and balls 62, to bring fthe motor 30, shaft V33, feed sleeve 42 and spindle 48 to rest, and the operating :cycle is shortened. The momentum of cage v49, ksockets 158 and balls :6.2 is absorbed, lwhen Athedrive is 'dis connected, by the spring 65, which returns the frusto-conical pusher member to its normal position. As the feeding pressure is withdrawn from the feed sleeve 42 by the return of the frustoconical pusher member, the feeding sleeve is likewise returned to the normal position by the spring 65. As it returns to normal position, the forward yend of feed sleeve 42 moves to the rear of the rear end of the collet 88, whereupon spring T3 becomes effective to cock the collet into the position shown in Fig. 1 and the automatic feeding mechanism is in a position for subsequent cycling operations.

I am aware that the feeding mechanism for rotary cutters described herein is susceptible of considerable variation without departing from the spirit of my invention and, therefore, I claim my invention broadly, as indicated by the appended claims.

Having thus described my invention, what I claim as new and useful, and desire to secure by Letters Patent, is:

l. In 9, centrifugal feed mechanism for rotary cutters including a driving shaft, a driven shaft, and means for driving the driven shaft from the driving shaft, means for automatically moving said driven shaft axially comprising the combination of a revoluble retainer driven by said driving shaft, a frusto-conical pusher member, a connection between said pusher member and said driven shaft whereby pressure exerted on said pusher member, upon rotation of said retainer, is transmitted to the driven shaft, a plurality of holders mounted in said retainer and movable radially outwardly and inwardly thereof in rey spect to the driving shaft, and rolling members .carried by said holders and movable radially outwardly and inwardly thereof in respect to the driving shaft and the holders for exerting pres- :sure on the pusher member to move the driven shaft axially, said rolling members and holders being permitted simultaneously to act as inertia masses to exert centrifugal force on the pusher member for an intermediate range of the axial movement of said pusher member.

2. In, a centrifugal feed mechanism for rotary cutters, the combination set forth in claim 1 in which means is provided at a predetermined point at the end of axial movement of the pusher member to prevent the holders from exertin any centrifugal force upon the pusher member.

3. In a centrifugal feed mechanism for rotary cutters including a driving shaft, a driven shaft, and means for driving the driven shaft from the driving shaft, means for automatically moving said driven shaft axially comprising the combination of a revoluble retainer driven by said driving shaft, a frusto-conical pusher member, a connection between said pusher member and said driven shaft whereby pressure exerted on said pusher member, upon rotation of said retainer, is transmitted to the driven shaft, a plurality of holders, each provided with a. socket, slidab-ly mounted in said retainer to move radially inwardly and outwardly thereof with respect to the driving shaft, a rolling member carried in each of the sockets of the holders and movable radially outwardly and inwardly theref with respect to the driving shaft and the holders for exerting pressure, in mass with the 7 rolling members only exerting pressure on the' pusher member, thereby reducing the centrifugal force exerted upon said 'pusher member toward the close of the axial movement of the driven shaft.

4. In a centrifugal feed for rotary cutters, the combination set forth in claim 3 in which the limiting means for the holders are pins on the retainer engaging notches in the holders.

5. In a centrifugal feed mechanism for rotary cutters, including a driving shaft, a driven shaft, and means for driving the driven shaft from the driving shaft, means automatically moving said driven shaft axially comprising the combination of a revoluble retainer driven by said driving shaft, a frusto-conical pusher member, a connection between said pusher member and said driven shaft whereby pressure exerted on said pusher member, upon rotation of said retainer, is transmitted to the driven shaft to move it axially, a, plurality of holders mounted in said retainer .and movable radially outwardly and nwardly thereof with respect to the driving shaft, rolling members carried by the holders and movable radially outwardly and inwardly relatively to said holders and the driving shaft for exerting pressure, in mass with the holders, on the pusher member to move the driving shaft axially, and means for limiting the outwardly radial movement of the holders in respect to the outward movement of the rolling members for reducing the pressure exerted upon the pusher member beyond a predetermined point in feeding direction.

6. In a centrifugal feed mechanism for rotary lcutters, including a driving shaft, a driven shaft, and means for driving the driven shaft from the driving shaft, means automatically moving said driven shaft axially comprising the combination of a revoluble retainer driven by said driving shaft, a frusto-conical pusher member, connection between said pusher member and said driven shaft whereby pressure exerted on said pusher member, upon rotation of said retainer, is transmitted to the driven shaft to move it axially, a. plurality of holders mounted in said retainer and movable radially outwardly and inwardly thereof with respect to the driving shaft, rollingv members carried lby the holders and movable radially outwardly and inwardly with respect to said holders and the driving shaft for exerting pressure, in mass with the holders, on the pusher member to move the driving shaft axially, means for retarding the initial outward radial movement of the holders for reducing initial pressure upon the pusher member, and means for limiting the outward radial movement of the holders in respect to the outward movement of the rolling members for reducing the pressure exerted upon the pusher member beyond a predetermined point in feeding direction.

PHILIP S. CLAUS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,703,061 Coleman Feb. 19, 1929 2,034,988 Nilsson et al. Mar. 24, 1936 2,038,450 Roesch Apr. 21, 1936 2,346,359 Claus Apr. 11, 1944 2,375,639 Falk May 8, 1945 

